In the structure of diborane,

1.	All hydrogen atoms lie in one plane and boron atoms lie in a plane perpendicular to this plane.
2.	2 boron atoms and 4 terminal hydrogen atoms lie in the same plane and 2 bridging hydrogen atoms lie in the perpendicular plane
3.	4 bridging hydrogen atoms and boron atoms lie in one plane and two terminal hydrogen atoms lie in a plane perpendicular to this plane
4.	All the atoms are in the same plane

Identify the correct resonance structures of carbon dioxide from one given below

a.  ${}^{-}\mathrm{O}-\mathrm{C}={\mathrm{O}}^{+}$

b.  $\mathrm{O}=\mathrm{C}=\mathrm{O}$

c.  ${}^{-}\mathrm{O}\equiv \mathrm{C}-{\mathrm{O}}^{+}$

d.  ${}^{-}\mathrm{O}-\mathrm{C}\equiv {\mathrm{O}}^{+}$

Choose the correct option:

1. (a, b)

2. (b, c)

3. (c, d)

4. (b, d)

A compound X, of boron, reacts with NH₃ on heating to give another compound Y which is called inorganic benzene. The compound X can be prepared by treating BF₃ with lithium aluminum hydride. The compounds X and Y are represented by the formulas.

1.  B₂H₆, B₃N₃H₆

2.  B₂O₃, B₃N₃H₆

3.  BF₃, B₃N₃H₆

4.  B₃N₃H₆, B₂H₆

Quartz is extensively used as a piezoelectric material, it contains-

1.  Pb

2.  Si

3.  Ti

4.  Sn

The most commonly used reducing agent among the following is :

1. AlCl₃ 

2. PbCl₂

3. SnCl₄

4. SnCl₂

Dry ice is-

1. Solid NH₃

2. Solid SO₂

3. Solid CO₂

4. Solid N₂

Cement, the important building material is a mixture of oxides of several elements. Besides calcium, iron, and sulphur oxides of elements of which of the group(s) are present in the mixture?

1. Group 2

2. Groups 2, 13, and 14

3. Groups 2, and 13

4. Groups 2, and 14

The reason for the small radius of Ga compared to Al is-.

a.  Poor screening effect of d and f orbitals

b.  Increase in nuclear charge

c.  Presence of higher orbitals

d.  Higher atomic number

Choose the correct option
1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)

The linear shape of CO₂ is due to _______.

a.  sp³ hybridisation of carbon

b.  sp hybridisation of carbon

c.  $\mathrm{p\pi }-\mathrm{p\pi }$ bonding between carbon and oxygen

d.  sp² hybridisation of carbon

Choose the correct option
1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)

Me₃SiCl is used during polymerization of organ silicones because

a.  Chain length of organic silicone polymers can be controlled by adding ${\mathrm{Me}}_3\mathrm{SiCl}$

b.  ${\mathrm{Me}}_3\mathrm{SiCl}$ blocks the end terminal of silicone polymer

c.  ${\mathrm{Me}}_3\mathrm{SiCl}$ improves the quality and yield of the polymer

4.  ${\mathrm{Me}}_3\mathrm{SiCl}$ acts as a catalyst during polymerization

Choose the correct option

1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)